ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation

Page 1 of 12

Document Title:

Summary Site Profile for the S-50 Liquid 

Thermal Diffusion Project

Document Number: ORAUT-TKBS-0054

Revision: 00

Effective Date: 12/08/2006

Type of Document: TBD

Supersedes: None

Subject Experts: Elizabeth A. Langille, Paul A. Szalinski, and Bill R. Thomas

Approval: Signature on File Approval Date: 12/04/2006

Paul A. Szalinski, Document Owner

Approval: Signature on File Approval Date: 12/04/2006

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 12/05/2006

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 12/06/2006

Kate Kimpan, Project Director

Approval: Brant A. Ulsh Signature on File for Approval Date: 12/08/2006

James W. Neton, Associate Director for Science

 New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 2 of 12

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION

NUMBER DESCRIPTION

12/08/2006 00 New document to describe the S-50 Liquid Thermal Diffusion Project

to enable the preparation of dose reconstructions. First approved 

issue. Attributions and Annotations added to document. 

Incorporates formal internal and NIOSH review comments. There is 

no change to the assigned dose and no PER is required. Training 

required: As determined by the Task Manager. Initiated by Paul A. 

Szalinski.
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 3 of 12

TABLE OF CONTENTS

TABLE TITLE

Acronyms and Abbreviations..................................................................................................................

PAGE

4

1.0 Introduction .................................................................................................................................5

1.1 Purpose.......................................................................................................................... 6

1.2 Scope............................................................................................................................. 6

2.0 Site Description...........................................................................................................................6

2.1 S-50 Liquid Thermal Diffusion Plant............................................................................... 6

2.2 Nuclear Energy for the Propulsion of Aircraft Project..................................................... 7

3.0 Occupational Medical Dose ........................................................................................................7

4.0 Occupational Environmental Dose............................................................................................10

5.0 Occupational Internal Dose.......................................................................................................10

6.0 Occupational External Dose .....................................................................................................10

7.0 Attributions and Annotations .....................................................................................................10

References ...........................................................................................................................................12

LIST OF TABLES

TABLE TITLE

3-1 Frequency of occupational chest X-rays....................................................................................

PAGE

8

3-2 X-ray equipment.........................................................................................................................8

3-3 Organ dose per X-ray procedure for X-ray examinations from 1944 to 1951 ............................ 9

3-4 Reference organs for IREP organs not included in ICRP Publication 34 ................................ 10
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 4 of 12

ACRONYMS AND ABBREVIATIONS

cGy centigray

d day

DOE U.S. Department of Energy

DCF dose conversion factor

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

ESE entrance skin exposure

ft foot

Gy gray

HVL half-value layer

ICRP International Commission on Radiological Protection

in. inch

IREP Interactive RadioEpidemiological Program

kV kilovolt

kVp kilovolts peak, applied kilovoltage

LAT lateral

lb pound

mm millimeter

NEPA Nuclear Energy for the Propulsion of Aircraft (Project)

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

PA posterior-anterior

POC probability of causation

psig pounds per square inch gage

R roentgen

S-50 S-50 Liquid Thermal Diffusion Project

SEC Special Exposure Cohort

SRDB Site Research Database

TBD technical basis document

U.S.C. United States Code

§ section or sections
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 5 of 12

1.0

Technical basis documents and site profile documents are not official determinations made by the 

National Institute for Occupational Safety and Health (NIOSH) but are rather general working 

documents that provide historic background information and guidance to assist in the preparation of 

dose reconstructions at particular sites or categories of sites. They will be revised in the event 

additional relevant information is obtained about the affected site(s). These documents may be used 

to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.

INTRODUCTION

In this document, the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)]. 

EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon 

which such building, structure, or premise is located ... in which operations are, or have been, 

conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises, 

grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. § 

7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted 

above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE 

facility encompassed by EEOICPA.

For employees of DOE or its contractors with cancer, the DOE facility definition only determines 

eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for 

members of the Special Exposure Cohort). The compensation decision for cancer claimants is based 

on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. § 

7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in the 

performance of duty for purposes of the compensation program if, and only if, the cancer ... was at 

least as likely as not related to employment at the facility [where the employee worked], as 

determined in accordance with the POC [probability of causation1

As noted above, the statute includes a definition of a DOE facility that excludes “buildings, structures, 

premises, grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982

(42 U.S.C. 7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. 

While this definition contains an exclusion with respect to the Naval Nuclear Propulsion Program, the 

section of EEOICPA that deals with the compensation decision for covered employees with cancer 

[i.e., 42 U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an 

exclusion. Therefore, the statute requires NIOSH to include all occupationally derived radiation 

exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including 

radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and 

external dosimetry monitoring results are considered valid for use in dose reconstruction. No efforts 

are made to determine the eligibility of any fraction of total measured exposure for inclusion in dose 

reconstruction. NIOSH, however, does not consider the following exposures to be occupationally 

derived:

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation

guidelines (nor the dose reconstruction regulation) define “performance of duty” for DOE employees 

with a covered cancer or restrict the “duty” to nuclear weapons work.

• Radiation from naturally occurring radon present in conventional structures

• Radiation from diagnostic X-rays received in the treatment of work-related injuries

 1 The U.S. Department of Labor is ultimately responsible under the EEOICPA for determining the POC.
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 6 of 12

1.1 PURPOSE

The purpose of this document is to provide guidance for dose reconstruction for EEOICPA-covered 

employees who participated in S-50 Liquid Thermal Diffusion Project (S-50) operations, specifically for 

non-SEC cancers and those presumptive cancer claims for workers who have fewer than 250 

workdays under this employment or in combination with workdays within the parameters established 

for other classes of employees in the SEC. 

An SEC class established for S-50 includes all employees of DOE predecessor agencies and their 

contractors and subcontractors who worked at S-50 from July 9, 1944, through December 31, 1951,

who were monitored or should have been monitored for exposure to ionizing radiation (NIOSH 2006). 

This SEC applies to workers with covered cancers who were employed for a number of workdays,

aggregating at least 250 workdays either solely under this employment or in combination with 

workdays within the parameters established for other classes of employees included in the SEC.

1.2 SCOPE

This site profile consists of seven sections: (1) Introduction, (2) Site Description, (3) Occupational 

Medical Dose, (4) Occupational Environmental Dose, (5) Occupational Internal Dose, 

(6) Occupational External Dosimetry, and (7) Attributions and Annotations.

2.0

2.1 S-50 LIQUID THERMAL DIFFUSION PLANT 

SITE DESCRIPTION

The S-50 Liquid Thermal Diffusion Plant was a wartime uranium enrichment facility constructed in 

1944 adjacent to the K-25 facility in Oak Ridge, Tennessee by H. K. Ferguson Company and 

operated by Fercleve Corporation, a wholly owned subsidiary of H. K. Ferguson Company that was 

organized for the sole purpose of operating the Plant. Groundbreaking for the facility was on July 9, 

1944, and construction was complete on October 31, 1944. The main process building dimensions 

were 522 ft long by 62 ft wide by 75 ft high; the building had a concrete floor and foundation, and steel 

frames, sides, and roof (MED 1947). Uranium enrichment began on September 16, 1944, before 

construction was complete. Thermal diffusion operations shut down on September 9, 1945 (DOE

2005).

There was a tremendous amount of emphasis placed on high production output at this facility. 

Processed uranium from the Plant was used as feed material for the Y-12 facility, where it was further 

enriched; some of this material was used in the bomb dropped over Hiroshima (“Little Boy”). 

Operations at S-50 generally continued around the clock. The number of individuals employed by 

Fercleve Corporation reached a maximum of more than 1,500 in April 1945 (MED 1947).

Feed material came from Harshaw Chemical Company of Cleveland, Ohio, in nickel shipping 

containers as uranium hexafluoride (UF6). The liquid thermal diffusion process at S-50 increased 235U 

enrichment from natural (0.71%) to 0.85% (MED 1947).

The process to enrich uranium at S-50 consisted of multiple columns, each of which contained three 

concentric pipes. High-pressure (1,000-psig) steam passed through the innermost nickel pipe, which 

was inside a copper pipe. UF6 was batch-charged into the gap between the nickel and copper pipes 

at about 1,500 psig. The nickel and copper pipes were inside the outermost steel pipe. Cold water 

passed between the steel pipe and the outer wall of the copper pipe. The enrichment process utilized 

convective flow, whereby the lighter 235U molecules tended to move upward along the hot nickel pipe 
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 7 of 12

wall while the heavier 238U molecules moved downward along the cold copper wall (MED 1947). A 

graph of the production output from S-50 (Percentage of Original Theoretical Maximum Output) 

showed the racks operated at less than 5% until January 1945, at which time the production 

increased gradually to a maximum of approximately 90% in June 1945 (MED 1947).

Losses of UF6 were common during S-50 operations, with UF6 often escaping into the air or cooling 

water (MED 1947). The losses usually resulted from internal or external breaks in columns or other 

parts of the process, which were caused by failure of the materials under the high operating 

pressures. Other losses resulted from improper handling of open connections and from operational 

mistakes due, in part, to the number of new employees at the facility and the emphasis on high 

production rates. From March through July 1945, monthly losses of UF6 ranged from 247 to 1,826 lb

(DOE 2005). Accountability records showing losses for other months of operation are unavailable. 

The released UF6 would rapidly oxidize and form uranyl fluoride (UO2F2) (DOE 2005), which would 

either exhaust through the building roof or settle to the process building floor. Operators were 

required to have a gas mask on their persons at all times for emergencies (MED 1947). 

The S-50 Plant ceased enrichment operation in September 1945, shortly after the war ended (MED 

1947). The uranium enrichment process used at S-50 was unique in that it was the only productionscale liquid thermal diffusion facility ever built. S-50 closed because it had become evident that the 

liquid thermal diffusion process would not be competitive with the gaseous diffusion process. 

Disassembly of the S-50 process equipment was done in the late 1940s, at which time it was removed 

from the main process building and transported to the K-25 Powerhouse Area, where it was stored for 

some time before being either salvaged or buried (DOE 2005). 

2.2 NUCLEAR ENERGY FOR THE PROPULSION OF AIRCRAFT PROJECT 

From May 1, 1946, through December 31, 1951, the S-50 facilities were used to conduct feasibility 

studies for the Nuclear Energy for the Propulsion of Aircraft (NEPA) project. The NEPA operations 

were conducted by Fairchild Engine and Aircraft Corporation (NIOSH 2006). The NIOSH Site 

Research Database (SRDB) and Internet searches yielded no data that described specific NEPArelated activities or the radiological conditions of the buildings occupied during these post-1945 

operations. 

However, some information was obtained through the telephone interviews with S-50 claimants and 

one follow-up interview with an S-50 claimant (NIOSH 2006). It was learned from these interviews 

that S-50 employees fabricated blocks that contained enriched uranium and graphite as potential fuel 

for a nuclear-powered airplane. In addition, the employees recovered enriched uranium using nitric 

acid solutions. The recovered enriched uranium was used to fabricate the uranium and graphite 

blocks. One interviewee stated, “the place was highly radioactive given the enriched 235U they were 

handling.” According to documented interviews with other claimants, activation analysis studies might

have taken place at S-50 on items that had been irradiated at the X-10 Plant. In addition, employees

during this period might have been exposed to contamination remaining from the earlier liquid thermal 

diffusion projects in this facility; NIOSH has no records that document decontamination of the facility 

at the conclusion of those operations (NIOSH 2006).

3.0

NIOSH (2006) concluded that adequate reconstruction of medical dose for S-50 workers is possible 

by using assumptions that are favorable to claimants in the TBDs for other Oak Ridge facilities 

(ORAUT 2004, 2006a,b for K-25, X-10, and Y-12, respectively) and the use of applicable protocols 

OCCUPATIONAL MEDICAL DOSE
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 8 of 12

specified in the complex-wide Technical Information Bulletin for dose reconstruction from 

occupationally related X-ray procedures (ORAUT 2005). 

It is assumed that the X-ray examination frequency and protocol was similar to that at K-25 because 

the S-50 facility was on the K-25 site (MED 1947). There are no specific data available on the S-50 

occupational medical evaluation program. Assumptions about X-ray examinations at S-50 derive from 

K-25 knowledge. Table 3-1 lists the nominal frequency of examinations over the years at S-50,

assuming the same protocol as that at K-25, during which work-related X-rays were required (ORAUT

2004). Some workers might have received occupational X-rays on a schedule different from that 

listed in the table. The reconstruction of occupational dose should include all occupational X-rays at

the frequency listed in Table 3-1 unless the individual-specific frequency is known and is more 

frequent than that in the table.

Table 3-1. Frequency of occupational chest X-rays

Period Frequency Comment

1944–1945 Annuala All employees

1946–1951 Annualb All employees

a. Monthly for some workers with potential for exposure to uranium 

dust.

b. Turner, James E., ORAU Team Consultant to Integrated 

Environmental Management, Inc., 2006. Every few months for some 

workers with potential for exposure to uranium dust.

This document assumes that S-50 followed K-25 medical practices, which followed the standards of 

radiology practice during the 1930s and 1940s (ORAUT 2004). The amount of dose received 

depends on the type of equipment, the technique factors, and the number of examinations typical in 

the early years (Cardarelli et al. 2002). The earliest X-rays at K-25 used the photofluorographic 

technique. Photofluorography had widespread use throughout the United States for tuberculosis 

screening in the 1930s and was state-of-the-art medical technology when work began at the gaseous 

diffusion plant as part of the Manhattan Project. 

Table 3-2 lists the X-ray equipment used at K-25 and the entrance skin exposure (ESE) produced by 

the machines (Cardarelli et al. 2002). The ESEs in Table 3-2 are from actual measurements made 

and documented in the literature.

Table 3-2. X-ray equipment (Cardarelli 2002).

Period X-ray machine kVp

Assumed HVL

(mm Al eq)

Image size 

(in.)

Entrance skin exposure (cGy)

PA

1944–1951 GE KX-10 80 2.5 4 × 5 2.488a

a. Quinn (1945); Cardarelli (2000).

Estimated organ doses for posterior-anterior (PA) chest X-rays were based on the dose conversion 

factors in International Commission on Radiological Protection (ICRP) Publication 34 (ICRP 1982). 

Lateral (LAT) chest x-rays were not performed. Organ doses from LAT chest radiography were 

greater than those from the corresponding PA doses based on the greater milliampere-second

exposure per radiograph and the smaller source-to-skin distance. 

ICRP (1982) contains tables of average absorbed dose (milligray) in selected organs for selected 

X-ray projections at a 1-Gy entrance kerma (i.e., air kerma without backscatter) for selected 

projections and beam qualities [i.e., various half-value layers (HVLs)]. These tables list the basic 

dose conversion factors for converting air kerma to organ dose. Air kerma was obtained from 

Table 3-2 for machine, projection, and period by assuming R = cGy (kerma). This assumption is 
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 9 of 12

conservative [1]. The estimation is made by Equation 3-1, where ESE is the entrance skin exposure 

in roentgens (numerically equivalent to centigray or rem), DCF is the dose conversion factor (stated 

as milliroentgen per roentgen, milligray per gray, or millirem per rem), and D is the dose in millirem.

ESE × DCF = D (3-1)

Table 3-3 lists the results of Equation 3-1 for the organs listed in ICRP (1982). The results of

Table 3-3 assume poor collimation, which means that some organs are included in the primary beam 

that would not normally be had the beam been properly collimated.

Table 3-3. Organ dosea per X-ray procedure for X-ray examinations from 

1944 to 1951.

Organ View

1944–1951

GE Model KX-10 Photofluorographic

4- × 5-in. 2.5-mm Al dose (rem)

Thyroid PA 4.33E-01b

Eye/brain PA 7.96E-02c

Ovaries PA 2.07E-02d

Testes PA 4.15E-03d

Lungs (male) PA 1.04E+00

Lungs (female) PA 1.12E+00

Breast PA 1.22E-01

Uterus PA 3.23E-03

Bone marrow (male) PA 2.29E-01

Bone marrow (female) PA 2.14E-01

Skin PA 3.36E+00e

a. Dose conversion factors from ICRP (1982, Tables A.2 through A.9).

b. Dose conversion factor for anterior-posterior cervical spine multiplied by depth dose 

correction factor of 0.2.

c. Dose conversion factor for PA chest.

d. The ovaries and testes values were obtained as follows: There are no DCFs in 

ORAUT (2005) for these organs at the early time. What was done was to multiply the 

generic organ doses (ORAUT 2005, Table 6-5, p. 22) by the ratio of the K-25 ESE 

(2.488 cGy from ORAUT 2004, Table 3.2-1) [2] and the generic entrance kerma of

3.0 cGy (ORAUT 2005, p. 20). This gives for the ovaries and testes, respectively,

2.5E-02 × (2.488 ÷ 3) = 2.07E-02 and

5.0E-03 × (2.488 ÷ 3) = 4.15E-03.

e. Entrance kerma multiplied by a backscatter factor of 1.35.

The Interactive RadioEpidemiological Program (IREP) computer program specifies organs for which 

there are no ICRP (1982) dose conversion factors. Organs not listed in Table 3-3 can usually be 

assigned doses by analogy of anatomical location – thorax, abdomen, and head/neck. The ICRP 

(1982) reference organs in these locations are lung, ovaries, and thyroid, respectively, as listed in 
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 10 of 12

Table 3-4. The dose for the analogous organ in Table 3-4 is assumed to be equal to that for the 

reference organ listed in Table 3-3 for the type of X-ray examination. Such a dose assignment will be

conservative because the analogue organ is more distant or more shielded than the reference organ.

Table 3-4. Reference organs for IREP organs not included in ICRP Publication 34.

Anatomical location ICRP 34 reference organ IREP organ analogues

Thorax Lung Thymus, esophagus, stomach, bone surface, 

liver/gall bladder/spleen, remainder organs

Abdomen Ovaries Urinary/bladder, colon/rectum

Head and neck Thyroid (unless otherwise specified) Eye, brain

4.0

NIOSH has been unable to find any environmental monitoring data from S-50 operations. NIOSH 

determined in the SEC Petition Evaluation Report (NIOSH 2006) that it lacks sufficient personnel 

monitoring, air monitoring, or source term data to adequately reconstruct any internal or external 

occupational exposures at the S-50 Plant. As a consequence, NIOSH finds that it is not feasible to 

estimate with sufficient accuracy the radiation doses from internal or external ambient exposures at 

the S-50 Plant.

OCCUPATIONAL ENVIRONMENTAL DOSE

5.0

Review of the available information concludes that bioassays were not obtained during the years of 

concern (1944 to 1951). This conclusion is based on the lack of information on bioassays and 

monitoring and the recommendations for treatment of exposures to workers and medical personnel 

when a worker “breathed process material” (MED 1947; Various ca. 1945). 

OCCUPATIONAL INTERNAL DOSE

NIOSH determined in the SEC Petition Evaluation Report (NIOSH 2006) that it lacks sufficient 

personnel monitoring, air monitoring, or source term data to adequately reconstruct the internal 

exposures at S-50. As a consequence, NIOSH finds that it is not feasible to estimate with sufficient 

accuracy the radiation doses from internal exposures during S-50 operations.

6.0

NIOSH considers the available external monitoring data and methods inadequate for performing 

external dose reconstruction at S-50. NIOSH determined in the SEC Petition Evaluation Report

(NIOSH 2006) that it lacks sufficient personnel monitoring, area monitoring, or source term data to 

adequately reconstruct the external exposures at S-50. As a consequence, NIOSH finds that it is not 

feasible to estimate with sufficient accuracy the radiation doses from external exposures during S-50

operations.

OCCUPATIONAL EXTERNAL DOSE

7.0

Where appropriate in this site profile, bracketed callouts have been inserted to indicate information, 

conclusions, and recommendations provided to assist in the process of worker dose reconstruction. 

These callouts are listed here in the Attributions and Annotations section with information provided to 

identify the source and justification for each associated item. Conventional references are provided in 

the References section that link data, quotations, and other information to documents available for 

review on the NIOSH Project computer network.

ATTRIBUTIONS AND ANNOTATIONS

[1] Cember, Herman, 1996, Introduction to Health Physics, McGraw-Hill, New York, New York. 

This document describes the relationship of kerma to dose.
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 11 of 12

[2] Turner, James E., ORAU Team Consultant to Integrated Environmental Management, Inc., 

2006.

The value 2.488 is called ESE in ORAUT (2004, Table 3-2-1), which one might assume to

mean roentgens of exposure. But because the unit centigray is specified in the table, the 

given value was assumed to be the kerma. The distinction would introduce a factor of 

0.876 rad for an exposure of 1 R.
Document No. ORAUT-TKBS-0054 Revision No. 00 Effective Date: 12/08/2006 Page 12 of 12

REFERENCES

Cardarelli, J. J., II, 2000, A Potential Consequence of Excluding Work-Related X-Ray Exposures 

when Computing Cumulative Occupational Radiation Dose at a Uranium Enrichment Plant, 

Dissertation, University of Cincinnati, Cincinnati, Ohio. [SRDB Ref ID: 11105]

Cardarelli, J., H. Spitz, C. Rice, R. Buncher, H. Elson, and P. Succop, 2002, "Significance of Radiation 

Exposure From Work-Related Chest X-Rays for Epidemiological Studies of Radiation 

Workers," American Journal of Industrial Medicine, volume 42, pp. 490–501. [SRDB Ref ID: 

4037, 11103, 11104]

ICRP (International Commission on Radiological Protection), 1982, Protection of the Patient in 

Diagnostic Radiology, Publication 34, Pergamon Press, Oxford, England.

MED (Manhattan Engineer District), 1947, Manhattan District History Book VI, Liquid Thermal 

Diffusion (S-50) Project, May 21. [SRDB Ref ID: 8623; contains Export Controlled 

Information]

NIOSH (National Institute for Occupational Safety and Health), 2006, SEC Petition Evaluation Report,

Petition SEC-00060, Office of Compensation Analysis and Support, Cincinnati, Ohio, August 

4.

ORAUT (Oak Ridge Associated Universities Team), 2004, Technical Basis Document for the K-25 

Site – Occupational Medical Dose, ORAUT-TKBS-0009-3, Rev. 00, Oak Ridge, Tennessee, 

June 29.

ORAUT (Oak Ridge Associated Universities Team), 2005, Dose Reconstruction from Occupationally 

Related Diagnostic X-Ray Procedures, ORAUT-OTIB-0006, Rev. 03 PC-1, Oak Ridge, 

Tennessee, December 21.

ORAUT (Oak Ridge Associated Universities Team), 2006a, Technical Basis Document for the Y-12 

Site – Occupational Medical Dose, ORAUT-TKBS-0014-3, Rev. 00 PC-3, Oak Ridge, 

Tennessee, April 18.

ORAUT (Oak Ridge Associated Universities Team), 2006b, Technical Basis Document for the Oak 

Ridge National Laboratory – Occupational Medical Dose, ORAUT-TKBS-0012-3, Rev. 01 

PC-1, Oak Ridge, Tennessee, July 21.

Prince, R. P., 2005, Compilation of Historical Document Reference Sources for Project S-50, Liquid 

Thermal Diffusion Plant, ETTP-736, Bechtel Jacobs Company, East Tennessee Technology 

Park, Oak Ridge, Tennessee, May. [SRDB Ref ID: 17169]

Quinn, B., 1945, “Mass Miniature Radiography of the Chest using 4x5 [Inch] Film,” Radiography, 

volume 11, number 125, pp. 33–37.

Various authors, ca. 1945, collection of memoranda and surveys related to radiation hazards and 

medical treatment at S-50. [SRDB Ref ID: 16643]